Key-switch



B. L. MOORE.

KEY SWITCH.

APPLICATION FILED Aue.24.191s.

1,341,719. Patented June 1 1920.

fir TOPNZY PATENT osr cs.

Briton L. MOORE, or BUFFALO, new ron'x.

KEY-SWITCH.

Specification of Letters Patent.

Patented June 1, 1920.

Application filed August 24,1918. Serial No. 251,213.

To all whom it may concern:

Be it known that I, BYRON L. MOORE, a

citizen of the United States of America,

and a resident of the city of Buffalo, county of Erie, and State of NewYork, have invented certain new and useful Key-Switches, of which thefollowing is a full, clear, and exact description. 1

My invention relates generally to key switches, which are used intelephone, radio telephone, and radio telegraph systems, sometimesreferred to as anti-capacity keys. It will be understood by thoseskilled in the art, that previous forms of similar-apparatus have beendetrimental, in that they have been constructed with flat springsinsulated from each other but facing each other in close proximity and,therefore, having considerable'electrostatic capacity. Due to this fact,these'keys, when the springs thereof were in oroutof mechanical contactwith each other, have permitted the passage of a perceptible amount ofinduced alternating current. It has, therefore, been difficult toentirely interrupt alternating currents, particularly those ofhigh-frequency with these previous forms of keys; it being well lmownthat two flat metal surfaces facing each other in close proximityseparated by a dielectricsuch as air or an insulating compound-act as acondenser with considerable apparent conductivity to alternatingcurrents of high-frequency.

The general object of my invention has been to provide a key or switchwhich shall overcome defects inherent in the keys of previousconstruction, with respect to the capacity effects just described.

Another object has been to provide a mounting for the master springs,which shall furnish air spaces around thesprings for the purpose ofreducing the electrostatic capacity.

Another object has been to provide a key of this nature which shall beof simple and rugged construction, and one cheap to manufacture.

The above objects and advantages have been accomplished by the deviceshown in the accompanying drawings, of which:

Figure .1 is a side elevation of the complete device; a portion thereofbeing shown in section.

Fig. 2 is a sectional elevation thereof,-

Fig. 3 is a sectional, plan view, taken on line 3-3 of Fig. 1.

Fig. 4 is a side elevation of one. of the master springs.

Fig. 5 shows a modified form of master spring.

Fig. 6 shows another form of master spring.

' My switch comprises an insulating block 5, which carries the contactsprings of the device. This block is carried by a frame 6, preferablyU-shape and having its ends 7 and 8 fastened to the block. 5. This framemay be made either of metal or insulating material. Carried by the topof the frame 6 is a cam actuating mechanism of the well known type, andpreferablycom prising a lever 10, a cam '11, and cam rollers rotationand the air spaces 28 are provided.

The upper .end 29 of each spring is bent inwardly toward the center of.the key and then outwardly, or otherwise formed so as to be;mechanically engaged by the rollers 12 and be actuated thereby. Theupper end 29 of each of the master springs is so angularly arranged thatwhen the cam actuating mechanism is operated, the rollers will be lockedin osition .until manually released.

isposed opposite and facing each of these master springs 13, and ofdifferent electrical polarity or potential, are one or more anvilsprings 14. These springs are also secured near their lower ends withinthe insulated block 5, and have their upper ends extending to near thetop of the master springs 13. The portion of the spring which engageswith the block may be knurled or roughened, but is preferably providedwith projecting tabs 30, which prevent the spring from rotating. Theanvil springs 14 are preferably cylindrical in shape and each has itsupper end portion bent inwardly so as to bring the end thereof in closeproximity to the masterspring, at the same time keeping the'greater partof the spring as distant as possible from the master spring, within thelimits of the construction. This construction affords a small area ofopposing surface and at the same time maintains a substantial distancebetween the springs referred to. As the result of this construction, mykey has the advantages of low electric capacity, mechanical rigidity ofthe anvil spring, and permits the adaptation of the spring end tocontact uses. 4

While I have shown and described the anvil springs of roundcross-section, they may, if desired, be of any other suitablecross-section, as diamond-shape or squareshape.

In Fig. 5, I show a modified form of master spring. In this figure, theupper end 9 of the spring 21, which contacts with the cam actuatingmechanism, is provided with a return bend 22 arranged in interspacedrelation. This construction provides means for dampening the -vibrationof the master spring when suddenly operated or released. In Fig. 6, Ishowanother form of spring end 23 for accomplishing the same purpose asthe form shown in Fig. 5. In this form, a piece of spring metal 20 isriveted to the upper end of the master spring 24:.

The master springs, instead of being formed of flat material, as shown,may be made of any other desirable cross-section, such as round, square,or diamond-shaped wire and may have their upper ends formed in anydesired manner.

t will be clear that when the cam lever is operated, the rollers 12 willcontact with the upper bent ends of 'the-master springs and move thesesprings intt) or out of elec trical contact with the anvil'springs.

It is obvious that while, for purposes of illustration, I have shown mykey provided with a certain number of springs, it may contain-any othernumber and arrangement of springs to adapt it for use in connectionwith'difi'erent electrical circuits; the lower ends of the springsbeing, of course, connected in the well known manner with the circuitsbeing controlled. It is also evident that the frame supporting themechanical parts may take any desired form or be constructed of a singlematerial or materials.

Having thus described my invention, what I claim is: i

-1. In a key switch, the combination, with a frame and a cam actuatingmechanism carried by the frame, of a block of insulatmg materialcarried'by the frame, master springs fastened near their lower endswithin the block and having their upper ends bent so as to bemechanically engaged by the cam actuating mechanism and be'actuatedthereby, anvil springs, each having the surface adjacent the masterspring of small, superficial area as compared to the area ofthe masterspring, said, anvil springs bein secured near their lower ends withinthe b ock, the upper ends of the anvil springs being bent toward theadjacent master springs so as to bring the upper end in close proximitythereto. 1

2. In a key switch, the combination, with a frame and a ca m actuatingmechanism carried by the frame, of a block of insulating materialcarried by the frame, -master springs fastened near their lower endswithin the block and having their upper ends' bent so as to bemechanically engaged by the cam actuatin mechanism and be actuatedthereby, anvi springs, cylindrical in cross section and secured neartheir lower ends within the block, the upper ends of the anvil springsbeing bent toward the adjacent master springs so as to bring the upperend in close proximity thereto.

3. In a key. switch, the combination, with a u shaped. frame and a camactuatin mechanism carried by the frame, of a bloc of insulatingmaterial carried at the lower end of the frame, master springs fastenednear their lower ends'within the block and having their upper ends bentso as to be mechanically engaged by the cam actuatin mechanism and beactuated thereby, an springs substantially, cylindrical in crosssectionand secured near their lower ends within the block, the upper ends ofthe anvil springs being bent toward the adjacentmaster spring so as tobring the upper ends a in close proximity thereto.

In testimony whereof I have hereunto si ed m name. I

'gn BYRON L. MOORE.v

